A&P Chapter 11: Part 1

Cardiovascular system

organ system that distributes blood to all parts of the body

Mediastinum

the region of the thoracic cavity between the lungs that holds the heart

Apex

pointed section of the heart that rests on the diaphragm

Base

broad section of the heart that lies beneath the second rib

Pericardium

the membranous sac enveloping the heart

Fibrous pericardium

loosely fitting superficial part of the pericardium

Parietal layer

lines the interior of the fibrous pericardium

Epicardium/visceral pericardium

a serous membrane that tightly hugs the external surface of the heart and is actually part of the heart wall

Pericarditis

inflammation of the pericardium

Endocardium

the endothelial membrane lining the interior of the heart

Atrium

a chamber of the heart receiving blood from the veins; superior heart chamber

Ventricles

discharging chambers of the heart

Interventricular septum

divides the heart longitudinally

Superior vena cava

transports blood to the heart from the upper body

Inferior vena cava

transports blood to the heart from the lower body

Pulmonary trunk

main artery off of right ventricle

Pulmonary arteries

carry blood to the lungs

Pulmonary veins

carry blood from the lungs to the heart

Aorta

takes oxygenated blood from left ventricle and brings it to the body; the major systemic artery

Systemic circulation

oxygenated blood returns from the lungs into the left atrium through the 4 pulmonary veins

Atrioventricular (AV) valves

prevent backflow into the atria when the ventricles contract

Bicuspid/mitral valve

the left AV valve the consists of two flaps

Tricuspid valve

the right AV valve that consists of three flaps

Chordae tendineae

tiny white cords that anchor the AV valve flaps to the walls of the ventricles

Semilunar valves

valves that prevent blood return to the ventricles after contraction

Pulmonary semilunar valve

valve between the right ventricle and pulmonary artery

Aortic semilunar valve

valve between the left ventricle and aorta

Endocarditis

an inflammation of the inner lining of the heart

Coronary arteries

arteries that branch from the base of the heart; blood supply that oxygenates and nourishes the heart

Angina pectoris

severe, suffocating chest pain caused by brief lack of oxygen supply to heart muscle

Myocardial infarction

a condition characterized by dead tissue areas in the myocardium caused by interruption in blood supply to the area

Infarct

a region of dead, deteriorating tissue resulting from a lack of blood supply

Sinoatrial (SA) node

the mass of specialized myocardial cells in the wall of the right atrium; pacemaker of the heart

Atrioventricular (AV) node

a specialized mass of conducting cells located at the atrioventricular junction in the heart

Atrioventricular bundle/Bundle of His

a bundle of modified heart muscle that transmits the cardiac impulse from the atrioventricular node to the ventricles causing them to contract

Bundle branches

right and left branches in the septum

Purkinje fibers

the modified cardiac muscle fibers of the conduction system of the heart

Pacemaker

a device that delivers electrical impulses to the heart to regulate the heartbeat

Heart block

impaired transmission of impulses from atrium to ventricle

Ischemia

a local decrease in blood supply

Fibrillation

irregular, uncoordinated contraction of muscle cells in the heart

Tachycardia

an abnormal, excessively rapid heart rate; over 100 beats per minute

Bradycardia

slow heartbeat, usually defined as a rate under 60 beats per minute

Systole

the contraction phase of heart activity

Diastole

a period (between contractions) of relaxation of the heart during which it fills with blood

Cardiac cycle

sequence of events encompassing one complete contraction and relaxation of the atria and ventricles of the heart

Mid to late diastole

first step in the cardiac cycle; blood flows from atria into ventricles

Ventricular systole

second step in the cardiac cycle; contraction of the ventricles

Early diastole

third step in the cardiac cycle; at the end of systole, atria finish refilling, ventricular pressure is low